Optical disk device

ABSTRACT

An object of the present invention is to perform a pickup feed operation and a turntable raising/lowering operation by the use of a rotatable drive source mechanism ( 54 ) for rotatably driving an optical disk including, for example, a CD while avoiding interference between an optical pickup ( 57 ) and the same drive source ( 54 ) in an optical disk device ( 1 ) for recording and reproducing a signal on the optical disk. To accomplish the above-mentioned object, a dual-purpose drive source mechanism ( 62, 64, 65, 66, 67, 68 ) generates a driving force for a pickup drive mechanism ( 57   a ) and a turntable raising/lowering mechanism ( 51   c,    15 ). The operation of switching a transmission path of the driving force of the dual-purpose drive source mechanism ( 62, 64, 65, 66, 67, 68 ) from a path leading to the pickup drive mechanism ( 57   a ) to a path leading to the turntable raising/lowering mechanism ( 51   c,    15 ), or vice versa is performed by an operation independent of the optical pickup ( 57 ) under the driving force of the dual-purpose drive source mechanism ( 62, 64, 65, 66, 67, 68 ).

TECHNICAL FIELD

The present invention relates to an optical disk device for recording asignal on an optical disk serving as an information recording mediumincluding, for example, a compact disk (a so-called “CD”) and a digitalversatile disk (a so-called “DVD”) and the like, or for reproducing arecorded signal.

BACKGROUND ART

Some optical disk devices are constructed to include a front panelformed with an opening through which a disk tray enters and exits. Insuch an optical disk device, after an optical disk is placed on the disktray exiting through the opening, the optical disk together with thedisk tray is drawn into a predetermined position inside the device.

In this type of disk device, after the optical disk is drawn and storedin the inside of the device, a turntable moves upwardly from apredetermined lowered position to a predetermined raised position, andthe optical disk is placed on the turntable and held between theturntable and a clamper. In this condition, the optical disk is thenrotated at a predetermined rpm by the rotation of the turntable.

For example, in a reproducing operation, a recording and reproducingdevice reproduces a signal recorded on the optical disk. Specifically,the reproduction of a predetermined information signal is carried out byreciprocally moving an optical pickup for signal reading between anouter region and an inner region of the optical disk in accordance withthe track position of the signal recorded in a predetermined area of theoptical disk.

An optical disk device of the above-mentioned type necessitates a totalof four basic operations requiring the driving force of a motor and thelike: a disk transport operation for reciprocally moving the disk trayinwardly or outwardly of the device to transport the optical diskinwardly or outwardly of the device; a turntable raising/loweringoperation for reciprocally moving the turntable between thepredetermined lowered position and the predetermined raised position; adisk rotating operation for rotatably driving the turntable to rotatethe optical disk; and a pickup feed operation for reciprocally movingthe optical pickup between the outer region and the inner region of theoptical disk.

Typically, of the above-mentioned four operations, the disk rotatingoperation and the pickup feed operation have been performed byrespective purpose-built motors, and the disk transport operation andthe turntable raising/lowering operation have been performedcontinuously by a single motor.

On the other hand, there is a prior art optical disk device such that asingle motor effects a total of three operation: the above-mentioneddisk transport operation, the above-mentioned turntable raising/loweringoperation and the above-mentioned pickup feed operation, so that all ofthe operations including the above-mentioned disk rotating operation areperformed by a total of two motors (see, for example, the publication ofJapanese Patent Application Laid-Open No. 2000-222803).

In this optical disk device, a power transmission mechanism switchingmechanism is operated in response to the operation of moving the opticalpickup further inwardly of the data area of the optical disk, to performswitching between a driving mechanism for the pickup feed operation anda driving mechanism for the turntable raising/lowering operation, fortransmission of the driving force of the motor.

However, the operation of the power transmission mechanism switchingmechanism itself is performed in response to the operation of moving theoptical pickup itself further inwardly of the data area of the opticaldisk in the optical disk device disclosed in the above-mentionedpublication. For switching between the pickup feed operation and theturntable raising/lowering operation, it is necessary to move theoptical pickup further widely inwardly from the data area of the opticaldisk. However, a spindle motor for the disk rotating operation isprovided near the center of an inner region of the optical disk.

For this reason, it is necessary to provide a space for movement of theoptical pickup between the mounting surface of the spindle motor and therear surface of the turntable to avoid the interference of the opticalpickup with an outer peripheral part of the spindle motor during theinward movement of the optical pickup from the data area of the opticaldisk.

To achieve this, for example, the spindle motor having a protrudingrotation shaft as long as about 20 mm from the mounting surface of thespindle motor is used (typically about 8 mm), and the optical pickupitself having a relatively thin structure with a height of less thanabout 20 mm is adopted.

However, the shaft runout of the rotation shaft increases in proportionto a distance from the mounting surface of the spindle motor to the rearsurface (or the disk holding surface) of the turntable (that is, thelength of the rotation shaft). As the distance increases, the amount ofeccentricity (the runout of the rotation axis) of the optical diskrotating integrally with the turntable accordingly increases. In someinstances, there is a danger that no signals can be recorded on theoptical disk or reproduced.

Further, the relatively thin optical pickup having a height of about 20mm, which is required to refract the optical path of a laser withrespect to the direction of the impingement of the laser on the opticaldisk, causes the addition of optical parts to result in increased costsas compared with an optical pickup of a non-refraction type. That is,there has been a problem that it is impossible to use an inexpensiveoptical pickup so that the device is not constructed at low costs.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide an optical diskdevice capable of avoiding interference between an optical pickup and arotatable drive source for rotatably driving the optical disk andcapable of performing a pickup feed operation and a turntableraising/lowering operation by using the same drive source.

A optical disk device according to the present invention is an opticaldisk device capable of storing and ejecting an optical disk forrecording or reproducing a signal on the optical disk stored therein,the optical disk device comprising: a turntable for rotatably supportingthe optical disk stored; a rotatable drive source mechanism forrotatably driving said turntable; a turntable raising/lowering mechanismfor vertically moving said turntable between a lowered position in whichinterference with the optical disk stored or ejected is avoided and araised position in which the optical disk stored is supportable; anoptical pickup for recording a signal on the optical disk supported bysaid turntable or reproducing a signal; a pickup drive mechanism forreciprocally moving said optical pickup between an inner region and anouter region of the optical disk supported by said turntable; adual-purpose drive source mechanism for generating a driving force forsaid turntable raising/lowering mechanism and said pickup drivemechanism; and a first operation switching mechanism for performing afirst switching operation for switching a transmission path of thedriving force of said dual-purpose drive source mechanism from a pathleading to said pickup drive mechanism to a path leading to saidturntable raising/lowering mechanism, or vice versa, wherein said firstoperation switching mechanism performs said first switching operation byan operation independent of said optical pickup under the driving forceof said dual-purpose drive source mechanism.

In the optical disk device according to the present invention, the firstoperation switching means performs the first switching operation by theoperation independent of the optical pickup under the driving force ofthe dual-purpose drive source mechanism. Thus, the optical pickup neednot be moved further toward the inner region of the optical disk duringthe first switching operation. This avoids the interference between theoptical pickup and the rotatable drive source mechanism while using thesame dual-purpose drive source to perform the pickup feed operation andthe turntable raising/lowering operation.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an optical disk device with a disk trayin an extended position as viewed from above in an oblique directionaccording to an embodiment of the present invention.

FIG. 2 is a perspective view of the optical disk device with the disktray in the extended position as viewed from below in an obliquedirection.

FIG. 3 is a perspective view of the optical disk device with the disktray in a retracted position as viewed from above in an obliquedirection.

FIG. 4 is a perspective view of the optical disk device with the disktray in the retracted position as viewed from below in an obliquedirection.

FIG. 5 is an exploded perspective view showing a traverse unit.

FIG. 6 is a perspective view showing a trigger plate 69.

FIG. 7 is a perspective view showing the traverse unit with an opticalpickup in a position of an outer region of an optical disk.

FIG. 8 is a perspective view showing the traverse unit with the opticalpickup moved to an innermost position.

FIG. 9 is a perspective view showing the traverse unit with a slide rackmoved further toward an inner region.

FIG. 10 is an exploded perspective view showing the optical disk device.

FIG. 11 is a perspective view showing a main chassis.

FIG. 12 is a perspective view showing a cam slider.

FIG. 13 is a perspective view showing a positional relationship betweenprincipal parts of the optical disk device with a turntable in an raisedposition.

FIG. 14 is a perspective view showing a positional relationship betweenthe principal parts of the optical disk device with the turntable in alowered position.

FIG. 15 is a perspective view showing the optical disk device in acondition before second operation switching.

FIG. 16 is a perspective view showing the optical disk device in acondition after the second operation switching.

FIG. 17 is a perspective view showing the optical disk device during theoperation of extending the disk tray.

FIG. 18 is a block diagram showing an example of a system constructedusing the optical disk device.

BEST MODE FOR CARRYING OUT THE INVENTION

<Basic Construction>

First, the general construction of an entire optical disk device will bedescribed. FIG. 1 is a perspective view of the optical disk device witha disk tray in an extended position as viewed from above in an obliquedirection. FIG. 2 is a perspective view of the optical disk device withthe disk tray in the extended position as viewed from below in anoblique direction. FIG. 3 is a perspective view of the optical diskdevice with the disk tray in a retracted position as viewed from abovein an oblique direction. FIG. 4 is a perspective view of the opticaldisk device with the disk tray in the retracted position as viewed frombelow in an oblique direction. For purposes of illustration, an axisparallel to directions in which the disk tray is extended and retractedis defined as a Y axis (the direction in which the disk tray isretracted is defined as a (+)Y direction, and the direction in which thedisk tray is extended is defined as a (−)Y direction), an axisorthogonal to the above-mentioned Y axis on a surface of the disk trayfor placing an optical disk thereon is defined as an X axis (therightward direction with respect to the positive (+) direction of the Yaxis is defined as a (+)X direction, and the leftward direction withrespect to the positive (+) direction of the Y axis is defined as a (−)Xdirection), and an axis orthogonal to the surface of the disk tray forplacing the optical disk thereon is defined as a Z axis (the directionin which the surface for placing the optical disk thereon faces isdefined as a (+)Z direction, and its opposite direction is defined as a(−)Z direction) throughout this embodiment.

This optical disk device 1 comprises a main chassis 11, and a traversechassis 51 pivotably supported by the main chassis 11.

The main chassis 11 is a component serving as a base body of thisoptical disk device 1. A disk tray 12 movable for extension andretraction, and a clamper 18 are mounted to the main chassis 11.

More specifically, the main chassis 11 has a rectangular frame element11 p capable of receiving the disk tray 12. The rectangular frameelement 11 p is formed with an opening 11 h through which the disk tray12 can pass.

The above-mentioned disk tray 12 is in the form of a substantiallyrectangular plate receivable in the above-mentioned rectangular frameelement 11 p. A receiving tray portion 12 f for placing an optical diskin a predetermined position of the disk tray is provided on one mainsurface side of the disk tray 12.

The disk tray 12 reciprocally moves along the directions of the Y axisto retract through the above-mentioned opening 11 h into the rectangularframe element 11 p of the main chassis 11 or to extend outwardly fromthe rectangular frame element 11 p. With the disk tray 12 extendedoutwardly from the main chassis 11, the optical disk is placed on thereceiving tray portion 12 f. Thereafter, the disk tray 12 moves toretract into the main chassis 11, whereby the optical disk is stored inthe optical disk device 1. With the optical disk stored in the opticaldisk device 1, the disk tray 12 moves to extend outwardly of the mainchassis 11, whereby the optical disk is ejected from this optical diskdevice 1.

A bridge piece 11 q is provided so as to extend between the oppositeside pieces of the main chassis 11. The clamper 18 is rotatablysupported by the bridge piece 11 q.

The clamper 18 is supported in a position upward (in the (+)Z direction)of the level of the path of movement of the disk tray 12 and the opticaldisk so as not to interfere with the disk tray 12 and the optical diskwhich reciprocally move along the directions of the Y axis. A magnet 17(see FIG. 10) is contained inside the clamper 18, and the clamper 18 anda turntable 52 to be described below attract each other because of themagnetic force of the magnet 17 to attach to and hold the optical disktherebetween.

The traverse chassis 51 is a base body of such size as to beaccommodated in the above-mentioned rectangular frame element 11 p asseen in plan view. A pivot axis side end portion of the traverse chassis51 toward which the disk tray 12 is retracted (in the (+)Y direction) issupported by the main chassis 11 pivotably about a predetermined pivotaxis P1 (see FIGS. 2 and 4).

The pivotable support is achieved, for example, by the followingconstruction. A pair of protruding rotation shafts 51 a and 51 bextending along the directions of the X axis are formed on oppositesides of the pivot axis side end portion of the traverse chassis 51. Themain chassis 11 includes a pair of bearing portions composed of shaftsupporting portions 11 a and 11 b of generally U-shaped configurationand elastically deformable shaft holding portions 11 c and 11 d, andcapable of rotatably holding the above-mentioned rotation shafts 51 aand 51 b (see FIG. 4). The pair of rotation shafts 51 a and 51 b aresupported by the above-mentioned pair of bearing portions rotatablyabout the above-mentioned pivot axis P1, whereby the traverse chassis 51is pivotably supported.

The turntable 52 is provided near the forward end of a pivotaldisplacement side end portion of the traverse chassis 51 toward whichthe disk tray 12 is extended (in the (−)Y direction). The turntable 52is formed of a material having the property of being attracted by amagnetic force of iron or the like, and the optical disk is held betweenthe turntable 52 and the clamper 18. In this condition, the turntable 52rotates integrally with the optical disk under the driving force of aspindle motor 54 (see FIG. 5) serving as a rotatable drive sourcemechanism to be described later.

An optical pickup 57 is supported by the traverse chassis 51 movablyalong the directions of the Y axis. This optical pickup 57 records asignal on the optical disk or reproduces a signal recorded on theoptical disk.

A portion composed of the traverse chassis 51 and various partsincluding the turntable 52, the optical pickup 57 and the like which areincorporated in the traverse chassis 51 is referred to hereinafter as atraverse unit 50, and a portion composed of other various parts, thatis, parts including the main chassis 11, the disk tray 12 incorporatedin the main chassis and the like is referred to hereinafter as a loadingunit 10 (see FIG. 10).

Next, the general operation of this optical disk device 1 will bedescribed.

As shown in FIG. 2, with the disk tray 12 extended outside this device1, the traverse chassis 51 provided with the turntable 52, the opticalpickup 57 and the like is pivoted about the rotation shafts 51 a and 51b in such a direction that the pivotal displacement side end portion ofthe traverse chassis 51 is spaced apart from the turntable 52 in orderto avoid interference with the optical disk drawn into the device 1 andthe turntable 52, and is in an inclined position with respect to themain chassis 11 (see FIG. 14).

After the disk tray 12 is moved to retract into the main chassis 11 by adisk transport mechanism (to be detailed later), the traverse chassis 51is pivoted about the pivot axis P1 into a position parallel to the mainchassis 11 by a turntable raising/lowering mechanism (to be detailedlater) at the time that the optical disk reaches a position directlyover the turntable 52 (see FIG. 13). This operation causes the turntable52 to move upwardly.

Because of the upward movement of the turntable 52, the clamper 18 isattracted to the turntable 52 by the force of attraction of the magnet17 therein, whereby the optical disk is held between the clamper 18 andthe turntable 52. In this condition, the rotatable driving of thespindle motor 54 to be described later which is directly coupled to theturntable 52 rotates the optical disk together with the turntable 52 ata predetermined rpm. Then, the optical pickup 57 is moved in apredetermined radial direction (in a direction of the Y axis in thefigures) of the optical disk by a pickup drive mechanism (to be detailedlater) to record an information signal on a predetermined data area onthe optical disk or reproduce an information signal. The optical disk,after the recording or reproduction of the information signal, isejected outwardly from the device 1 by sequentially reversing theabove-mentioned operations.

<Description about Traverse Unit>

The construction of the traverse unit 50 will be described in furtherdetail. FIG. 5 is an exploded perspective view showing the traverse unit50. As described above, the traverse chassis 51 is a component servingas the base body of the traverse unit 50, and is formed with theabove-mentioned pair of protruding rotation shafts 51 a and 51 b on theopposite sides of the pivot axis side end portion thereof, and a drivenboss portion 51 c protruding from an end surface of the pivotaldisplacement side end portion of the traverse chassis 51. The drivenboss portion 51 c is provided in a first cam groove 15 a of a cam slider15 serving as a slider member, which will be detailed later, so that thetraverse chassis 51 is pivoted in response to the extending andretracting movements of the disk tray 12.

The turntable 52 and the spindle motor 54 are provided near theabove-mentioned pivotal displacement side end portion of the traversechassis 51.

The spindle motor 54 is fixed to the traverse chassis 51, with arotation shaft 54 a thereof directed toward the disk tray 12 side. Thetip of the rotation shaft 54 a is pressed into the central hole of theturntable 52, whereby the turntable 52 is rotatably supported on thedisk tray 12 side of the traverse chassis 51. The rotatable driving ofthe spindle motor 54 rotates the turntable 52.

The optical pickup 57 is provided on the disk tray 12 side of thetraverse chassis 51 and between the above-mentioned turntable 52 and thepivot axis side end portion. The traverse chassis 51 is formed with arequired opening in a region wherein the optical pickup 57 is disposedand its front and rear regions arranged in the directions of the Y axisso as to prevent interference with the optical pickup 57.

The optical pickup 57 is guided and supported movably along thedirections of the Y axis by a main shaft guide 60 extending along thedirections of the Y axis.

Specifically, the main shaft guide 60 is formed to have a rod-shapedconfiguration. One end portion ((+)Y direction side end portion) of themain shaft guide 60 is fixed to the traverse chassis 51 by a flat headscrew 61, and the other end portion ((−)Y direction side end portion) ofthe main shaft guide 60 is fitted, supported and fixed in a bearing hole(not shown) formed in the traverse chassis 51. One side portion of theoptical pickup 57 is slidably inserted and supported in a longitudinallyintermediate portion of the main shaft guide 60, whereby the opticalpickup 57 is supported movably along the directions of the Y axis (seeFIGS. 7 to 9). The other side portion of the optical pickup 57 is formedas a sliding portion slidable on the traverse chassis 51.

A rack portion 57 a is provided on the one side portion of the opticalpickup 57 and outside the main shaft guide 60. A slide rack 58 movablealong the directions of the Y axis with respect to the rack portion 57 ais provided on the rack portion 57 a.

The slide rack 58 is formed with rack teeth similar in arrangement andconfiguration to the rack teeth of the above-mentioned rack portion 57a, and a small gear portion 64 b of a feed gear 64 is adapted formeshing engagement with the rack portion 57 a and the slide rack 58.

The length of a region in which the rack teeth of the slide rack 58 areformed in the longitudinal direction (the direction of movement) thereofis greater than the length of a region in which the rack teeth of theabove-mentioned rack portion 57 a are formed. The slide rack 58 is urgedalong the direction of the Y axis toward the rack portion 57 a by aspring 59 serving as an urging means. Specifically, the urging force ofthe spring 59 is applied so that an end portion, closer to the innerregion of the optical disk, of the region in which the rack teeth of theslide rack 58 are formed substantially conforms with an end portion,closer to the inner region of the optical disk, of the region in whichthe rack teeth of the rack portion 57 a are formed and so that an endportion, closer to the outer region of the optical disk, of the regionin which the rack teeth of the slide rack 58 are formed slightlyprotrudes from an end portion, closer to the outer region of the opticaldisk, of the region in which the rack teeth of the rack portion 57 a areformed. Thus, the small gear portion 64 b of the feed gear 64 will be inmeshing engagement with both the rack portion 57 a and the slide rack 58during the recording or reproduction of information on the optical disk(see FIG. 7). In a first switching operation stage (to be describedlater) before and after the recording or reproduction of information onthe optical disk, the rack portion 57 a moves toward the inner region ofthe optical disk than the inward position within the range of movementthereof during the above-mentioned information recording or reproduction(that is, moves to an innermost position slightly inward of the inwardposition within the range of movement thereof during the above-mentionedinformation recording or reproduction). This causes the region in whichthe rack teeth of the rack portion 57 a are formed to be positionedcloser to the inner region of the optical disk than the small gearportion 64 b of the feed gear 64, to release the meshing engagementbetween the rack portion 57 a and the small gear portion 64 b while themeshing engagement is maintained between the slide rack 58 and the smallgear portion 64 b.

A switch pressing portion 57 b is provided on a turntable 52 side endportion (that is, an end portion closer to the inner region of theoptical disk stored in this device 1) of the rack portion 57 a. With therack portion 57 a moved to the above-mentioned innermost position, theswitch pressing portion 57 b presses a second switch 72 to be describedlater. In this condition, the optical pickup 57 or the rack portion 57 aabuts against a fixed member on the traverse chassis 51 side so that theoptical pickup 57 or the rack portion 57 a is inhibited from moving inthe (−)Y direction.

Also in this condition, the feed gear 64 continues rotating in apredetermined direction to enable the slide rack 58 to move in the (−)Ydirection with respect to the rack portion 57 a against the urging forceof the spring 59, with the rack portion 57 a maintained in a fixedposition. When the feed gear 64 is rotated in a direction opposite fromthe above-mentioned predetermined direction to move the slide rack 58 inthe (+)Y direction in the above-mentioned condition, the slide rack 58is moved by the spring 59 in such a manner as to be attracted in the(+)Y direction, whereby the small gear portion 64 b is brought intomeshing engagement with the rack portion 57 a.

It should be noted that the spring 59 also has the function ofpreventing backlash during the meshing engagement between the slide rack58 and the small gear portion of the feed gear 64. An end portion of theslide rack 58 closer to the turntable 52 (closer to the inner region ofthe optical disk) is formed with a protruding boss portion 58 aengageable with a cam groove 69 b of a trigger plate 69 to be describedlater.

A dual-purpose motor 62 is provided in a portion of the traverse chassis51 on one side of the optical pickup 57. The dual-purpose motor 62 isused as a drive source for the disk transport operation, the turntableraising/lowering operation and the pickup feed operation. Thedual-purpose motor 62 is fixed to the traverse chassis 51 by a screw 73,and has a rotation shaft pressed in a worm gear 63.

Further, the feed gear 64 is rotatably supported by the traverse chassis51. The feed gear 64 has a large gear portion 64 a which is a lowerhelical gear, and the small gear portion 64 b which is an upper spurgear. The large gear portion 64 a is adapted for meshing engagement withthe worm gear 63, and the small gear portion 64 b is adapted for meshingengagement with the rack portion 57 a of the optical pickup 57 and theslide rack 58 without backlash.

A first gear 65, a second gear 66, a third gear 67 and a fourth gear 68are rotatably supported by the traverse chassis 51.

The first gear 65 has a large gear portion 65 a which is a lower spurgear, and a small gear portion 65 b which is an upper spur gear. Thesecond gear 66 has a spur gear portion 66 a. The third gear 67 has apair of spur gear portions 67 a substantially identical in the number ofteeth and in tooth module with each other over and under a disk portion67 c having a predetermined diameter (although the lower spur gearportion is not shown). The fourth gear 68 has a spur gear portion 68 a,and is positioned so that a circumferential portion of the spur gearportion 68 a extends outwardly of the outer perimeter of the traversechassis 51 beyond the contour thereof. The spur gear portion 68 a isalways in meshing engagement with a tray gear 13 (to be described later)on the main chassis 11 to be described later.

The large gear portion 65 a of the first gear 65 is in meshingengagement with the large gear portion 64 a of the feed gear 64. Thesmall gear portion 65 b of the first gear 65 is in meshing engagementwith the spur gear portion 66 a of the second gear 66. The spur gearportion 66 a of the second gear 66 is in meshing engagement with thelower spur gear portion of the third gear 67. The lower spur gearportion of the third gear 67 is further in meshing engagement with thespur gear portion 68 a of the fourth gear 68. The feed gear 64, thefirst gear 65, the second gear 66, the third gear 67 and the fourth gear68 constitute a power transmission mechanism for transmitting thedriving force to each mechanism under the rotatable driving force of thedual-purpose motor 62. The power transmission mechanism and thedual-purpose motor 62 constitute a dual-purpose drive source mechanismfor generating the driving force for each mechanism.

By appropriately combining these gears 64, 65, 66, 67 and 68, therotation of the dual-purpose motor 62 is decelerated down to a desiredrpm and transmitted to the gears 64, 65, 66, 67 and 68.

The trigger plate 69 is supported on the pivotal displacement side endportion of the traverse chassis 51 movably substantially along thedirections of the X axis. FIG. 6 is a perspective view showing thetrigger plate 69.

This trigger plate 69 is formed to have a entirely substantiallyelongated configuration, and is provided with a protruding boss portion69 a engageable with the cam slider 15 to be described later in one sideportion on one end thereof. The boss portion 69 a is also inserted in aguide groove 11 f on the main chassis 11 side, whereby this triggerplate 69 is guided and supported.

The other end portion of the trigger plate 69 is formed with a recessedportion 69 g of a substantially U-shaped configuration. A singleprotruding tooth portion 69 d is formed on one side portion of therecessed portion 69 g. The upper spur gear portion 67 a of theabove-mentioned third gear 67 rotates in the recessed portion 69 g,whereby the tooth portion 69 d comes into meshing engagement with thespur gear portion 67 a. This causes the trigger plate 69 to move in apredetermined direction under the driving force of the above-mentioneddual-purpose motor 62.

The cam groove 69 b is formed in the other end portion of the triggerplate 69 and in the other side portion closer to an intermediate portionof the trigger plate 69 than the above-mentioned recessed portion 69 g.The cam groove 69 b is formed in the shape of a groove engageable by theboss portion 58 a of the slide rack 58, and is bent midway in adirection in which the cam groove 69 b extends. The slide rack 58 movesin the (−)Y direction, and the boss portion 58 a is inserted in the camgroove 69 b and moves in the cam groove 69 b, whereby the boss portion58 a is guided in a direction corresponding to the bending shape of thecam groove 69 b.

A protruding malfunction prevention wall 69 c is formed in the other endportion of the trigger plate 69 and outside the cam groove 69 b. Themalfunction prevention wall 69 c performs the function of abuttingagainst the boss portion 58 a of the slide rack 58 to inhibit themovement of the trigger plate 69 in the (+)X direction when the opticalpickup 57 is positioned closer to the inner region of the disk withinthe range of movement thereof during the recording or reproduction ofinformation, that is, prior to a second switching operation.

A relay substrate 70 is mounted on the opposite side of the traversechassis 51 from the disk tray 12. The relay substrate 70 is a substrateto which connection lines from the spindle motor 54 and the dual-purposemotor 62 are connected. The relay substrate 70 is provided with a firstswitch 71 for detecting the extended position of the disk tray 12 byusing the displacement of the cam slider 15 to be described later, andthe second switch 72 for detecting that the optical pickup 57 ispositioned closer to the inner region of the disk or that the raisingoperation of the turntable 52 is completed by using the displacement ofthe switch pressing portion 57 b of the optical pickup 57.

The pickup feed operation in the traverse unit 50 thus constructed willbe first described. FIG. 7 is a perspective view showing the traverseunit 50 with the optical pickup in a position of the outer region of theoptical disk during the pickup feed operation.

First, when the worm gear 63 is rotated by the rotatable driving forceof the dual-purpose motor 62, the large gear portion 64 a of the feedgear 64 is rotated in a direction depending on the rotation of thedual-purpose motor 62 by the worm gear 63. Because of the meshingengagement between the small gear portion 64 b of the feed gear 64 andthe rack portion 57 a of the optical pickup 57, the rotation of the feedgear 64 is transmitted to the optical pickup 57 in the form of a drivingforce for moving the optical pickup 57 along the direction of the Y axisalong the main shaft guide 60. Thus, the optical pickup 57 reciprocallymoves along the Y axis in accordance with the direction of rotation ofthe dual-purpose motor 62. For example, for the reproduction operation,the optical pickup 57 moves to a predetermined position in which aninformation signal desired to be read is recorded on the optical disk,and reproduces the information signal. A mechanism including the rackportion 57 a constitutes the pickup drive mechanism for reciprocallymoving the optical pickup 57 between the inner region and the outerregion of the optical disk.

In this operation, the slide rack 58 also reciprocally moves along the Yaxis in the same direction as the optical pickup 57 because of themeshing engagement between the small gear portion 64 b of the feed gear64 and the slide rack 58.

This optical disk device 1 has the following advantage because the wormgear 63 is press-fitted on the rotation shaft of the dual-purpose motor62 and the worm gear 63 is brought into meshing engagement with thelarge gear portion 64 a of the feed gear 64 to rotate the feed gear 64.

Typically, a spur gear is often mounted on the rotation shaft of a motorserving as a drive source for the pickup feed operation. In this case,the spur gear of the rotation shaft will be brought into meshingengagement with another spur gear for the optical pickup feed operation.

However, in the case of a high-speed search for data on the opticaldisk, the rpm of the motor reaches thousands of revolutions per minute,and harsh rattle noise occurs due to tooth pitch error between the spurgear on the rotation shaft side of this motor and the spur gear inmeshing engagement with the above-mentioned spur gear. Thus, measuresare taken to suppress the above-mentioned rattle noise, for example, byusing a relatively soft material such as nylon for the latter spur gear.However, the material such as nylon is very costly, and requires thecost of material about five times higher than that of, for example,polyacetal and the like which is most typically used as the material ofa plastic gear.

The dual-purpose motor 62 of this optical disk device 1, on the otherhand, reduces the tendency to cause the harsh rattle noise due to thetooth pitch error because the feed gear 64 meshing with the worm gear 63is sufficiently decelerated down to about hundreds of revolutions perminute even if the rpm of the dual-purpose motor 62 reaches thousands ofrevolutions per minute during the search operation as described above.This provides the advantage of being able to achieve a very quiet pickupfeed operation even by the use of a typical plastic material and thelike, rather than the costly material such as nylon and the like, forthe feed gear 64.

Next, a first switching operation for transition from the pickup feedoperation to the turntable raising/lowering operation in the traverseunit 50 will be described.

FIG. 8 is a perspective view showing the traverse unit 50 with theoptical pickup 57 moved to the innermost position. FIG. 9 is aperspective view showing the traverse unit 50 with the slide rack 58moved further in the (−)Y direction after the condition shown in FIG. 8.

When the optical pickup 57 is positioned in the outer region of theoptical disk as shown in FIG. 7, the optical pickup 57 is moved in the(−)Y direction by the rotation of the dual-purpose motor 62, and movesto the inward position of the data area of the optical disk.

Thereafter, when the optical pickup 57 moves to the innermost positionfurther in the (−)Y direction, the boss portion 58 a of the slide rack58 comes into engagement with the cam groove 69 b of the trigger plate69 in such a manner as to move into the cam groove 69 b near theinnermost position (see the arrow Q1 of FIG. 7). Thus, the trigger plate69 becomes movable in the (+)X direction as the boss portion 58 a movesin the (−)Y direction (see the arrow Q2 of FIG. 8).

With the optical pickup 57 reaching the inner end position of theoperation stroke, the second switch 72 of the optical pickup 57 pressesthe switch pressing portion 57 b, whereby it is detected that theoptical pickup 57 is positioned in the inner end position of theoperation stroke. At the same time, the meshing engagement between therack portion 57 a of the optical pickup 57 and the small gear portion 64b of the feed gear 64 is released, and a transition is made to themeshing engagement between the slide rack 58 and the small gear portion64 b. At the same time, the upper spur gear portion 67 a of the thirdgear 67 is placed in the recessed portion 69 g of the trigger plate 69.

In the subsequent operation, switching is done from the pickup feedoperation to the turntable raising/lowering operation in the firstswitching operation.

As the dual-purpose motor 62 continues further rotating, only the sliderack 58 moves in the (−)Y direction against the urging force of thespring 59 because of the meshing engagement with the above-mentionedsmall gear portion 64 b, with the optical pickup 57 placed in a fixedposition, as shown in FIG. 9, since the optical pickup 57 is alreadypositioned on the inner end of the operation stroke and the meshingengagement between the rack portion 57 a of the optical pickup 57 andthe small gear portion 64 b of the feed gear 64 is released.

This movement of the slide rack 58 causes the boss portion 58 a to exerta driving force on the cam groove 69 b of the trigger plate 69, therebymoving the trigger plate 69 in the (+)X direction. The cam slider 15 tobe described later operates in response to the movement of the triggerplate 69 to thereby start the raising/lowering operation of theturntable 52. The operation of the cam slider 15 will be detailed later.

In the course of the movement of the trigger plate 69 because of themeshing engagement between the small gear portion 64 b of the feed gear64 and the slide rack 58, the meshing engagement between the toothportion 69 d of the trigger plate 69 and the upper spur gear portion 67a of the third gear 67 is initiated (see FIG. 8). Subsequently, thetrigger plate 69 is moved in the (+)X direction also by the meshingengagement between the tooth portion 69 d on the trigger plate 69 sideand the upper spur gear portion 67 a of the third gear 67 (see the arrowQ2 of FIG. 8). That is, the trigger plate 69 in the course of themovement is moved in the (+)X direction both by the driving forcetransmitted from the feed gear 64 through the slide rack 58, the bossportion 58 a and the cam groove 69 b and the driving force transmittedfrom the third gear 67 through the upper spur gear portion 67 a thereofand the tooth portion 69 d.

In the course of the further movement of the trigger plate 69 in the(+)X direction, the meshing engagement between the slide rack 58 and thefeed gear 64 is released. Then, the trigger plate 69 is moved in the(+)X direction by the driving force transmitted from the third gear 67through the upper spur gear portion 67 a thereof and the tooth portion69 d (see FIG. 9). The meshing engagement between the tooth portion 69 dand the third gear 67 is also released just before the trigger plate 69further moved in the (+)X direction reaches the end thereof. Thesubsequent operation will be described later.

Components including the above-mentioned slide rack 58 and the triggerplate 69 constitute a first operation switching mechanism.

It should be noted that the speed at which the slide rack 58 moves thetrigger plate 69 by means of the engagement between the boss portion 58a and the cam groove 69 b and the speed of the upper spur gear portion67 a of the third gear 67 on a pitch circle (in other words, the speedat which the third gear 67 moves the trigger plate 69) are designed tobe substantially the same. The intermittent meshing engagement betweenthe tooth portion 69 d of the trigger plate 69 and the above-mentionedthird gear 67 is effected smoothly in accordance with the speed ofmovement caused by the driving force transmitted from the feed gear 64through the slide rack 58, the boss portion 58 a and the cam groove 69b.

The switching operation for transition from the turntableraising/lowering operation to the pickup feed operation in the traverseunit 50 is performed by reversing the above-mentioned operation.

<Description about Loading Unit>

Next, the construction of the loading unit 10 will be described infurther detail. FIG. 10 is an exploded perspective view showing thisoptical disk device. This loading unit 10 comprises the main chassis 11,the disk tray 12, the cam slider 15, and the clamper 18.

The main chassis 11 is a component serving as a base body of the opticaldisk device 1 or the loading unit 10. FIG. 11 is a perspective rear viewshowing the main chassis as viewed from below in an oblique direction.

A portion of the rectangular frame element 11 p of the main chassis 11which is opposed to an end surface of the traverse unit 50 toward whichthe tray is extended (in the (−)Y direction) is formed with a guidegroove 11 e engageable with the driven boss portion 51 c of the traversechassis 51, and the guide groove 11 f engageable with the boss portion69 a of the trigger plate 69. The pivot side end portion of the traversechassis 51 is moved and guided by the movement of the driven bossportion 51 c in the guide groove 11 e. The trigger plate 69 is guided bythe movement of the boss portion 69 a in the guide groove 11 f.

The one main surface of the disk tray 12 is formed with the recessedreceiving tray portion 12 f for holding the optical disk in apredetermined position, and the other main surface thereof is formedwith a rack portion 12 a and a tray guide groove extending along thedirections in which the disk tray 12 is extended and retracted (in thedirections of the Y axis) (see FIG. 2). The disk tray performs theoperation of reciprocally moving along the directions of the Y axis withrespect to the main chassis 11 to store and eject the optical disk bymeans of a disk tray carrying-out mechanism including the rack portion12 a.

The above-mentioned tray guide groove is constructed to include a firstguide groove 12 b provided in an end portion toward which the disk tray12 is extended ((−)Y direction side end portion), a third guide groove12 d extending from the end portion toward which the disk tray 12 isextended to an end portion toward which the disk tray 12 is retracted((+)Y direction side end portion), a second guide groove 12 c providedbetween the first guide groove 12 b and the third guide groove 12 d, anda fourth guide groove 12 e provided in the end portion toward which thedisk tray 12 is retracted, the first to fourth guide grooves 12 b to 12e being provided continuously and integrally (see FIG. 2). Theabove-mentioned first guide groove 12 b extends along a directionorthogonal to the directions in which the disk tray 12 is extended andretracted, and the third guide groove 12 d extends along theabove-mentioned directions in which the disk tray 12 is extended andretracted. The second guide groove 12 c extends between theabove-mentioned first guide groove 12 b and the third guide groove 12 dalong a direction angled with respect to the above-mentioned directionsin which the disk tray 12 is extended and retracted.

The tray gear 13 is rotatably supported by a supporting shaft portion 14in one side portion of the end portion of the main chassis 11 towardwhich the disk tray 12 is extended (in the (−)Y direction). The traygear 13 has a small gear portion 13 b always meshing with the fourthgear 68 on the traverse unit 50, and a large gear portion 13 aintermittently meshing with the rack portion 12 a formed on the disktray 12 side. Whether the small gear portion 13 b and the large gearportion 13 a are large or small means whether the pitch circle radiithereof are large or small. That is, the pitch circle radius of thesmall gear portion 13 b is smaller than the pitch circle radius of thelarge gear portion 13 a. The number of teeth of the large gear portion13 a and the number of teeth of the small gear portion 13 b are equal toeach other.

The above-mentioned disk tray 12 is incorporated in the main chassis 11so as to be able to be extended out of or retracted into the mainchassis 11 through the opening 11 h of the main chassis 11, with therack portion 12 a in meshing engagement with the large gear portion 13 aof the tray gear 13.

The cam slider 15 is supported in the end portion of the main chassis 11toward which the tray is extended (in the (−)Y direction) for reciprocalmovement along directions (directions of the X axis) orthogonal to thedirections in which the disk tray 12 is extended and retracted. FIG. 12is a perspective view showing the cam slider 15.

The cam slider 15 has a substantially L-shaped configuration such that asecond piece 15 q of a substantially plate-like shape is extensionallyprovided on one side portion of a first piece 15 p of a substantiallyelongated plate-like shape.

The second piece 15 q is formed with the first cam groove 15 a forengagement with the driven boss portion 51 c of the traverse chassis 51,and a second cam groove 15 b for engagement with the boss portion 69 aof the trigger plate 69. The first cam groove 15 a and the second camgroove 15 b each have an inclined groove portion extending graduallyaway from the first piece 15 p (or extending gradually away from thedisk tray 12 when incorporated in the main chassis 11) in a directionfrom one end to the other end of the cam slider 15 (in the (−)Xdirection).

The second piece 15 q is formed with a protruding switch pressingportion 15 e for pressing the first switch 71 on the traverse chassis 51in accordance with the movement along the direction of the X axis.

One end portion of the first piece 15 p, on the other hand, is formedwith a groove portion 15 g of a substantially U-shaped configurationcapable of receiving the small gear portion 13 b of the tray gear 13therein, and a rack portion 15 d provided in a forward end portion of aninner peripheral side portion of the groove portion 15 g forintermittently meshing with the small gear portion 13 b of the tray gear13. The rack portion 15 d is not formed in an inner portion of thegroove portion 15 g. Thus, the small gear portion 13 b is adapted formeshing engagement with the rack portion 15 d in the forward end portionof the groove portion 15 g, and is adapted to rotate freely withoutmeshing engagement with the rack portion 15 d in the inner portion ofthe groove portion 15 g.

The one end portion of the first piece 15 p is formed with a protrudingboss portion 15 c for sequential engagement with the guide grooves 12 b,12 c, 12 d, 12 e of the disk tray 12.

This cam slider 15 is supported on the end portion of the main chassis11 toward which the tray is extended for reciprocal movement along thedirections of the X axis, with the small gear portion 13 b of the traygear 13 received in the groove portion 15 g and the boss portion 15 cinserted and received in the guide grooves 12 b, 12 c, 12 d, 12 e of thedisk tray 12.

A torsion spring 16 serving as an urging member is attached to the endportion of the main chassis 11 toward which the tray is extended. Oneend of the torsion spring 16 is fixed to the main chassis 11, and theother end thereof is fixed to the cam slider 15 (see FIGS. 15 to 17).The urging force of the torsion spring 16 enables the cam slider 15 tohold its position at the start and end of the operation stroke in the(+)X direction.

A hole portion is formed substantially in the center of the bridge piece11 q of the main chassis 11, and the clamper 18 is mounted substantiallyin the center of a main surface the bridge piece 11 q on the disk tray12 side. The clamper 18 is mounted in a position out of the path of theextending and retracting movements of the disk tray 12 so as not tointerfere with the disk tray 12 during the extending and retractingmovements of the disk tray 12. The magnet 17 is contained inside theclamper 18, and optical disk is held between the clamper 18 and theturntable 52 by the force of attraction of the magnet 17.

The above-mentioned traverse unit 50 when assembled to the loading unit10 is in the following condition.

The pair of rotation shafts 51 a and 51 b of the traverse chassis 51 arerotatably supported by the pair of bearing portions (composed of theshaft supporting portions 11 a, 11 b and the shaft holding portions 11c, 11 d) on the main chassis 11 side, whereby the traverse chassis 51 issupported pivotably with respect to the main chassis 11.

The fourth gear 68 is in meshing engagement with the small gear portion13 b of the tray gear 13. This causes the disk tray 12 to make theextending and retracting movements with respect to the main chassis 11in accordance with the rotation of the fourth gear 68.

The driven boss portion 51 c of the traverse chassis 51 is in engagementwith the first cam groove 15 a of the cam slider 15. This causes thetraverse chassis 51 to pivot between a position in which the traversechassis 51 is close to the disk tray 12 (a position in which thetraverse chassis 51 is substantially parallel to the disk tray 12 or aturntable raised position) and a position in which the traverse chassis51 is remote from the disk tray 12 (an inclined position in which theend portion of the traverse chassis 51 toward which the disk tray 12 isextended is remote or a turntable lowered position) in accordance withthe movement of the cam slider 15 in the X direction.

The boss portion 69 a of the trigger plate 69 is in engagement with thesecond cam groove 15 b of the cam slider 15. This causes the cam slider15 to reciprocally move in the directions of the X axis in accordancewith the movement of the trigger plate 69 in the directions of the Yaxis.

Next, the turntable raising/lowering operation will be described.

As described above, the turntable raising/lowering operation isperformed at the time that the slide rack 58 starts moving the triggerplate 69.

FIG. 13 is a perspective view showing a positional relationship betweenprincipal parts of the optical disk device with the turntable in itsraised position. FIG. 14 is a perspective view showing a positionalrelationship between the principal parts of the optical disk device withthe turntable in its lowered position.

Specifically, immediately before the start of the movement of thetrigger plate 69, the boss portion 69 a of the trigger plate 69 ispositioned in a vertical groove portion (an end on the disk tray 12side) of the second cam groove 15 b of the cam slider 15, and the drivenboss portion 51 c of the traverse chassis 51 is positioned in an upperhorizontal groove portion (an end on the disk tray 12 side) of the firstcam groove 15 a of the cam slider 15. This causes the traverse unit 50to maintain a substantially horizontal position with respect to the disktray 12, that is, causes the turntable 52 to maintain the raisedposition.

In this condition, the cam slider 15 is urged in the (−)X direction bythe torsion spring 16, and is positioned on the side of the (−)Xdirection within its movable range. Therefore, the small gear portion(not shown) of the tray gear 13 is outside the groove portion 15 g ofthe cam slider 15, and the rack portion 15 d of the cam slider 15 is notin meshing engagement with the small gear portion of the tray gear 13.

When the trigger plate 69 in this condition moves in the (+)X direction,the boss portion 69 a of the trigger plate 69 transmits a force to thevertical groove portion of the second cam groove 15 b of the cam slider15, and the cam slider 15 under this force moves similarly in the (+)Xdirection. As the cam slider 15 moves further, the rack portion 15 d ofthe cam slider 15 comes into meshing engagement with the small gearportion of the tray gear 13, and the cam slider 15 moves in the (+)Xdirection for a while under the driving forces from both the triggerplate 69 and the tray gear 13.

After the trigger plate 69 moves in the (+)X direction and the meshingengagement between the tooth portion 69 d of the trigger plate 69 andthe upper spur gear portion 67 a of the third gear 67 is released (seeFIG. 9), the cam slider 15 is moved in the (+)X direction by the drivingforce through the tray gear 13. This movement of the cam slider 15 inthe (+)X direction causes the driven boss portion 51 c of the traversechassis 51 to be guided in a slant of the first cam groove 15 a of thecam slider 15 in a direction away from the disk tray 12. This causes thetraverse chassis 51 to pivot about the rotation shafts 51 a and 51 b ina direction away from the disk tray 12, thereby moving the turntable 52to the lowered position.

Components including the above-mentioned driven boss portion 51 c andthe cam slider 15 constitute the turntable raising/lowering mechanism.

Principal parts of the above-mentioned operation will be described infurther detail.

The traverse chassis 51 does not pivot while the driven boss portion 51c of the traverse chassis 51 is placed in the upper horizontal groove(the end on the disk tray 12 side) of the first cam groove 15 a of thecam slider and the driven boss portion 51 c moves the cam slider 15 inthe (+)X direction within the upper horizontal groove of the first camgroove 15 a. This allows the rack portion 15 d of the cam slider 15 andthe small gear portion of the tray gear 13 to come into meshingengagement at relatively low load in the early stage of the meshingengagement. During this interval, the boss portion 69 a of the triggerplate 69 moves within a horizontal groove portion (an end portion on thedisk tray 12 side) of the guide groove 11 f of the main chassis 11.

Next, the traverse chassis 51 starts pivoting about the rotation shaft51 a and 51 b in the stage wherein the rack portion 15 d of the camslider 15 and the small gear portion of the tray gear 13 are in fullymeshing engagement with each other and the driven boss portion 51 c ofthe traverse chassis 51 moves within the slant groove portion which isan intermediate portion of the first cam groove 15 a of the cam slider15. This causes the turntable 52 to start lowering against the force ofattraction from the clamper 18 side.

During this interval, the boss portion 69 a of the trigger plate 69 isfirst moved within a slant groove portion which is an intermediateportion of the guide groove 11 f of the main chassis 11 by the movementof the cam slider 15 in the (+)X direction and the movement of thetraverse chassis 51 in the (−)Z direction. Then, the boss portion 69 aof the trigger plate 69 moves in a vertical groove portion of the guidegroove 11 f of the main chassis 11 (see FIG. 11) at a position whereinthe meshing engagement between the trigger plate 69 and the upper spurgear portion of the third gear 67 is released (see FIG. 9). Therefore,after the position wherein the meshing engagement between the triggerplate 69 and the upper spur gear portion 67 a of the third gear 67 isreleased, the cam slider 15 moves in the (+)X direction, but the bossportion 69 a of the trigger plate moves in the vertical groove portionof the guide groove 11 f of the main chassis 11, whereby the triggerplate 69 and the upper spur gear portion of the third gear 67 aremaintained out of meshing engagement with each other as shown in FIG. 9.

The switching from the turntable raising/lowering operation to a pickuptransport operation is done by reversing these operations.

Next, the operation of a second operation switching mechanism during atransition from the turntable raising/lowering operation to the disktransport operation will be described.

FIG. 15 is a perspective view showing the optical disk device in acondition before second operation switching. FIG. 16 is a perspectiveview showing the optical disk device in a condition after the secondoperation switching. FIG. 17 is a perspective view showing the opticaldisk device during the operation of extending the disk tray. For ease ofunderstanding, the tray 12 is shown in FIGS. 15 and 16 using only therack portion 12 a and the guide grooves 12 b, 12 c, 12 d and 12 e.

When the turntable 52 is in the raised position, the cam slider 15 ispositioned on the end of its operation stroke range toward the (−)Xdirection, and is urged in the direction of the (−)X axis by the torsionspring 16. The boss portion 15 c of the cam slider 15 is in engagementwith the guide groove 12 b of the tray 12. This prevents the disk tray12 from bursting out in the (−)Y direction by an external force and thelike.

In this condition, the large gear portion 13 a of the tray gear 13 isnot in meshing engagement with the rack portion 12 a of the tray 12.

When the lowering operation in the raising/lowering operation of theturntable 52 starts, the cam slider 15 is moved in the (+)X direction inresponse to the operation of the trigger plate 69, and the rack portion15 d of the cam slider 15 first comes into meshing engagement with thesmall gear portion 13 b of the tray gear 13. After this meshingengagement, the rotation of the small gear portion 13 b of the tray gear13 moves the cam slider 15 further in the (+)X direction. In response tothe movement of the cam slider 15, the boss portion 15 c of the camslider 15 moves in the (+)X direction from the guide groove 12 b to theguide groove 12 c. When the boss portion 15 c reaches the guide groove12 c angled with respect to the X axis and moves within the guide groove12 c, the movement of the boss portion 15 c in the (+)X direction istransformed into a force for moving the disk tray 12 in the (−)Ydirection. This moves the disk tray 12 to extend a predetermined amountout of the main chassis 11, thereby bringing the rack portion 12 a ofthe tray 12 into meshing engagement with the large gear portion 13 a ofthe tray gear 13. Thereafter, the second operation switching iscompleted by the release of the meshing engagement between the rackportion 15 d of the cam slider 15 and the small gear portion 13 b of thetray gear 13.

That is, such a configuration that the above-mentioned boss portion 15 cmoves in the guide grooves 12 b, 12 c and 12 d achieves the function asthe second operation switching mechanism.

The switching operation from the disk transport operation to theturntable raising/lowering operation is performed by reversing theabove-mentioned operations.

After the completion of the above-mentioned second operation switching,the operation of extending the disk tray 12 (the operation of ejectingthe tray), that is, the transport operation of the optical disk isperformed by the meshing engagement between the rack portion 12 a andthe large gear portion 13 a of the tray gear 13.

During the interval that the boss portion 15 c is engaged and guided bythe guide groove 12 d of the tray 12 in the operation of extending thedisk tray 12, as shown in FIG. 17, the position of the cam slider 15 inthe direction of the X axis is restricted and the cam slider 15 is urgedin the direction of the (+)X axis by the torsion spring 16. In aposition immediately short of the completion of the ejection of the disktray 12, the boss portion 15 c of the cam slider 15 is moved in the (+)Xdirection by the guide groove 12 e of the tray 12. This movement causesthe switch pressing portion 15 e of the cam slider 15 to press the firstswitch 71 on the traverse chassis 51, whereby the ejection position ofthe tray 12 is detected and the rotation of the dual-purpose motor 62 isstopped.

In the above-mentioned second operation switching operation, it isnecessary to prevent a situation wherein a shift occurs in the positionsof the cam slider 15 and the rack portion 12 a of the disk tray 12relative to each other. That is, in a position wherein the meshingengagement between the large gear portion 13 a of the tray gear 13 andthe rack portion 12 a of the disk tray 12 is initiated, the cam slider15 is required to have been moved to a predetermined position whereinthe meshing engagement between the rack portion 15 d of the cam slider15 and the small gear portion 13 b of the tray gear 13 is releasable. Ifthe cam slider 15 has not yet reached the above-mentioned predeterminedposition or has been beyond the predetermined position in the positionwherein the meshing engagement between the large gear portion of thetray gear 13 and the rack portion 12 a of the tray 12 is initiated, theabove-mentioned second operation switching operation does not normallyoperates due to the interference between the boss portion 15 c and theguide grooves 12 c, 12 d and the like.

Therefore, the phases of the small gear portion 13 b of the tray gear 13for driving the cam slider 15 and the large gear portion 13 a of thetray gear 13 for driving the disk tray 12 must not be in an arbitraryrelationship. In this embodiment, the large gear portion 13 a and thesmall gear portion 13 b of the tray gear 13 are equal in the number ofteeth to each other and differ in tooth module from each other.Therefore, there are no changes in the phases of the large gear portion13 a and the small gear portion 13 b. No relative position shift occursbetween the cam slider 15 and the rack portion 12 a of the disk tray 12in each second switching operation. The second operation switchingalways operates normally.

On the other hand, the raising/lowering operation of the turntable isperformed relatively slowly because the cam slider 15 is driven by thesmall gear portion 13 b of the tray gear 13. Therefore, theraising/lowering operation of the turntable which is prone to unusualnoise can be performed quietly. The disk transport operation, on theother hand, is performed relatively at high speed because the disk tray12 is driven by the large gear portion 13 a.

Next, operation until the reproduction of the information signal on theoptical disk after the storage of the disk tray 12 within the device 1will be described.

Specifically, the dual-purpose motor 62 rotates in a direction oppositefrom the direction of rotation made during the above-mentioned diskcarrying-out operation, and the disk tray 12 is stored into the device 1by the disk transport mechanism.

The cam slider 15 moves in response to the disk tray 12 reaching apredetermined position in the device 1 to release the meshing engagementbetween the large gear portion 13 a of the tray gear 13 and the rackportion 12 a of the tray 12, and the cam slider 15 moves to bring thesmall gear portion 13 b of the tray gear 13 into meshing engagement withthe rack portion 15 d. This completes the second switching operation.

Thereafter, the driving force of the dual-purpose motor 62 istransmitted from the tray gear 13 through the cam slider 15 and thedriven boss portion 51 c as a force for raising the turntable 52,thereby to raise the turntable 52. When the optical disk is lifted fromthe disk tray 12 by raising the turntable 52, the optical disk is heldbetween the turntable 52 and the clamper 18 by the force of attractiondue to the magnetic force of the clamper 18.

When the above-mentioned cam slider 15 continues moving further, themeshing engagement between the rack portion 15 d of the cam slider 15and the small gear portion 13 b of the tray gear 13 is released inresponse thereto, and the slide rack 58 moves to come into meshingengagement with the small gear portion 64 b of the feed gear 64 (thefirst switching operation). This causes the driving force of thedual-purpose motor 62 to be transmitted from the feed gear 64 throughthe slide rack 58 as a force for moving the optical pickup 57. Thismakes the optical pickup 57 movable in the direction toward the outerregion of the optical disk.

When the optical pickup 57 moves a predetermined amount toward the outerregion of the optical disk, the pressing of the second switch 72 by theswitch pressing portion 57 b of the optical pickup is released, and itis detected that the optical pickup 57 has been moved to a positioncloser to the outer region than the inner end of the operation stroke.After this detection condition, the optical pickup 57 can reproduce theinformation signal on the disk, and the rotation of the dual-purposemotor 62 is temporarily stopped in this position.

Then, the optical disk is rotated at a predetermined rpm by the spindlemotor 54 directly coupled to the turntable 52, and the optical pickup 57is moved by the pickup drive mechanism in a radial direction of the disktoward a position where desired data is present, to reproduce theinformation signal on the optical disk.

After the optical disk is stored, the position in which the opticalpickup 57 first reads the information signal is a pressing releaseposition in which the pressing of the second switch 72 by the switchpressing portion 57 b of the optical pickup 57 is released. Thispressing release position is outside, preferably slightly outside, ofthe innermost of the data area. After reading positional information onthe optical disk in the pressing release position, the optical pickup 57is moved once to the innermost position of the data area on the opticaldisk, based on the positional information. The optical pickup 57 moveson the optical disk with respect to this innermost position to reproducethe information signal in any position on the optical disk.

<Operation During Power-On and -Off of Optical Disk Device>

Next, operation during power-on and -off of this optical disk devicewill be described. When, for example, a system with this optical diskdevice 1 incorporated therein is powered off after the completion of thereproduction of the information signal, a power-off signal is providedto a controller of this optical disk device. This rotatably drives thedual-purpose motor 62 to cause the optical pickup drive mechanism tomove the optical pickup 57 to a position where the second switch 72 ispressed by the switch pressing portion 57 b. Thereafter, this opticaldisk device is also powered off.

On the other hand, when the system with this optical disk device 1incorporated therein is powered on, a power-on signal is provided to adrive controller 82 (to be described later) of this optical disk device1. Thus, the drive controller 82 rotatably drives the dual-purpose motor62 to cause the optical pickup drive mechanism to move the opticalpickup 57 to the pressing release position where the pressing of thesecond switch 72 by the switch pressing portion 57 b is released. Theoptical pickup 57 reads the positional information on the optical diskin this pressing release position, and is thereafter moved to theinnermost position of the data area, based on the positionalinformation. The optical pickup 57 moves on the optical disk withreference to the innermost position after the movement to reproduce theinformation signal on the optical disk.

If the second switch 72 is not pressed by the switch pressing portion 57b of the optical pickup 57 when the power-on signal is provided to thisoptical disk device, the drive controller 82 causes the pickup drivemechanism to instantaneously drives the optical pickup 57 to the outerregion of the optical disk, and then moves the optical pickup 57 to theposition where the second switch 72 is pressed by the switch pressingportion 57 b. Then, the pickup drive mechanism moves the optical pickup57 to the pressing release position where the pressing of the secondswitch 72 by the switch pressing portion 57 b is released, and causesthe optical pickup 57 to read the positional information on the disk inthis position. Thereafter, the optical pickup 57 is moved to theinnermost position of the data area, based on the positionalinformation, to reproduce the information signal on the disk withreference to the innermost position after the movement.

As discussed above, the optical pickup 57 is once moved to the outerregion of the optical disk if the second switch 72 is not pressed by theswitch pressing portion 57 b of the optical pickup 57. This is toprevent the simultaneous execution of the feed operation of the opticalpickup 57 and the lowering operation of the turntable 52, therebyincreasing the reliability of the operation.

Specifically, the condition wherein the second switch 72 is not pressedby the switch pressing portion 57 b of the optical pickup p57 refers toa condition wherein the optical pickup is on the data area of theoptical disk and is positioned to be able to reproduce the informationsignal of the optical disk. It is assumed that, in this condition, thesmall gear portion 13 b of the tray gear 13 and the rack portion 15 d ofthe cam slider 15 become meshingly engageable with each other for somereason. If, in this condition, the dual-purpose motor 62 rotates todrive the optical pickup 57 toward the inner region of the optical disk,the lowering operation of the turntable 52 is performed at the same timeby the rotation of the dual-purpose motor 62, whereby the normaloperation of the optical disk device is not achieved.

Even in such a condition, however, instantaneously driving the opticalpickup 57 once toward the outer region as described above causes thetooth portion 69 d of the trigger plate 69 to move at high speed in sucha manner as to be kicked by the third gear 67. Thus, the cam slider 15operating in response to the trigger plate 69 is moved from the positionwherein the small gear portion 13 b of the tray gear 13 and the rackportion 15 d of the cam slider 15 is meshingly engageable to an originalposition wherein they are not meshingly engageable, and also is urged bythe torsion spring 16 toward the position wherein they are not meshinglyengageable. Therefore, the feed operation of the optical pickup 57 andthe lowering operation of the turntable 52 are not performed at the sametime, which increases the reliability of the operation.

<Operation under Application of External Force to Optical Disk Device>

Next, operation will be described, for example, when this optical diskdevice is subject to an external force such as a vibration, an impactand the like during the transportation of a system with this opticaldisk device 1 incorporated therein.

Typically, the system with this optical disk device 1 incorporatedtherein is packed and transported, with the disk tray 12 stored in thedevice 1 and the second switch 72 pressed by the switch pressing portion57 b of the optical pickup 57.

In this case, it is conceivable that a force will act to move the camslider 15 to the position where the small gear portion of the tray gear13 and the rack portion 15 d of the cam slider 15 are meshinglyengageable because of a vibration and an impact during thetransportation. In this case, a disadvantage results such that the feedoperation of the optical pickup 57 and the lowering operation of theturntable 52 are performed at the same time as described above.

In this optical disk device 1, however, the cam slider 15 is urged bythe torsion spring 16 so as to be held in the original position (whereinthe small gear portion 13 b of the tray gear 13 and the rack portion 15d of the cam slider 15 are not in meshing engagement with each other).The above-mentioned disadvantage is prevented.

Further, in this optical disk device 1, while the second switch 72 ispressed by the switch pressing portion 57 b of the optical pickup 57,the malfunction prevention wall 69 c abuts against the boss portion 58 aof the slide rack 58 to inhibit the movement of the slide rack 58, andthe cam slider 15 is inhibited from moving in a direction wherein thesmall gear portion 13 b of the tray gear 13 and the rack portion 15 d ofthe cam slider 15 is meshingly engageable. Therefore, theabove-mentioned simultaneous execution of the feed operation of theoptical pickup 57 and the lowering operation of the turntable 52 isprevented.

<Connection and Construction of Electrical Components in Optical DiskDevice>

This optical disk device 1 comprises the spindle motor 54, thedual-purpose motor 62, the first switch 71, the second switch 72 and therelay substrate 70 in addition to the optical pickup 57 as electricalcomponents thereof.

FIG. 18 is a block diagram of a system constructed using this opticaldisk device 1. As shown in FIG. 18, a signal read by the optical pickup57 is outputted through a signal processor 81 to the outside, or apredetermined signal is provided through the signal processor 81 to theoptical pickup 57. A detection output from each of the first switch 71and the second switch 72 is provided to the drive controller 82, and thepositional information read by the optical pickup 57 is provided throughthe signal processor 81 to the drive controller 82. The driving controlof the spindle motor 54 and the dual-purpose motor 62 are effectedthrough a driving circuit not shown under the control of the drivecontroller 82. The above-mentioned signal processor 81 and the drivecontroller 82 may be incorporated in an external device (substrate)connected through the relay substrate 70 as will be described later, orbe incorporated in the relay substrate 70 itself.

The connection lines from the spindle motor 54 and the dual-purposemotor 62 are attached to the rear surface of the traverse chassis 51(opposite from the disk tray 12) and are directly soldered to the relaysubstrate 70. The above-mentioned first switch 71 and second switch 72are directly mounted on the relay substrate 70.

In this optical disk device, the motors 54, 62 and switches 71, 72required to drive and control the entire device 1 are all disposed onthe traverse unit 50 and are connected in a concentrated manner to therelay substrate 70 mounted to the traverse unit 50. This enables theelectrical interconnect lines to be extracted together and connected toan electrical circuit outside the device, thereby establishingconnection between the electrical components of this optical disk deviceand the external electrical circuit except the optical pickup 57.Therefore, the electrical connection is facilitated when this opticaldisk device is incorporated in the system.

In general, the first switch 71 for detecting whether the disk tray 12is extended or retracted is often mounted on the loading unit 10 side.In this case, a connection line with connectors is used to establishconnection between the first switch 71 and the electrical circuitoutside the device, or a connection line from the first switch 71 issoldered to the relay substrate 70 on the traverse unit 50 using aconnection line. In the former case, the connection line with connectorsis required to be connected to two portions of the electrical circuitoutside the device. In the latter case, the connection line is subjectto a bending force because of the pivotal movement of the traverse unit50 caused by the raising/lowering operation of the turntable, and mightbe broken after prolonged use.

In this optical disk device 1, because the first switch 71 is disposedon the traverse unit 50 and is pivoted together with the relay substrate70 mounted to the traverse unit 50, an electrical interconnect line forconnection therebetween is not subject to the bending force as describedabove. Therefore, the problem of a break in the electrical connectionafter prolonged use does not arise.

Additionally, the first switch 71 and the second switch 72, which aredisposed directly on the relay substrate 70, eliminate the need forconnection lines to aid in constructing the device at low costs.

In the optical disk device constructed as mentioned above, the switchingbetween the pickup feed operation and the turntable raising/loweringoperation is done by an operation independent of the optical pickup 57,that is, the operation of the slide rack 58 moving toward the innerregion of the optical disk, and does not need the operation of furthermoving the optical pickup 57 further toward the inner region.

It is therefore unnecessary to use a thin optical pickup as used in aconventional optical disk device, and an optical disk device isconstructed using a thick and inexpensive optical pickup. Further, thedual-purpose motor 62 may have a relatively short rotation shaft toreduce the runout of the rotation shaft of the optical disk.

The movement of the trigger plate 69 is driven through both the sliderack 58 and the third gear 67 midway through the movement thereof. Thus,the trigger plate 69 can be subject to a sufficient driving force. Thisensures the first operation switching and the turntable raising/loweringoperation.

The conversion speed of the trigger plate 69 by the above-mentionedslide rack 58 and the circumferential speed of the third gear on thepitch circle are designed to be equal to each other. This providessmooth intermittent meshing engagement between the tooth portion 69 d ofthe trigger plate 69 and the above-mentioned third gear.

The traverse unit 50 of this optical disk device 1 may be used as atraverse unit for an optical disk device of a portable type and anoptical disk device of an auto-changer type if the five components, i.e.the first gear 65, the second gear 66, the third gear 67, the fourthgear 68 and the trigger plate 69, are removed.

For example, two component, i.e. a worm gear and a motor, may be addedto this optical disk device 1 to directly drive the tray gear 13,thereby driving the disk tray transport mechanism and the turntableraising/lowering mechanism, whereas the above-mentioned five componentsand the torsion spring 16 be removed instead. In such a case, theoptical disk device comprising a very small number of components isachieved.

In other words, the optical disk device described in this embodiment canperform all of the operations of the optical disk device by means of twomotors by adding four components (the six components added minus the twocomponents removed) to the above-mentioned optical disk device usingthree motors as the drive source. Of the components constituting theoptical disk device, motors are very costly as compared with mechanicalcomponents such as gears. In ordinary cases, about 30 gears can beeasily procured at the cost of one motor, depending on the number ofproductions. Therefore, the optical disk device according to the presentinvention can be constructed at very low cost, as compared with anoptical disk device of the type employing three motors as the drivesource.

While the invention has been shown and described in detail, theforegoing description is in all aspects illustrative and notrestrictive. It is therefore understood that numerous modifications andvariations can be devised without departing from the scope of theinvention.

1. An optical disk device capable of storing and ejecting an opticaldisk for recording or reproducing a signal on said optical disk storedtherein, comprising: a main chassis; a disk tray movable to extend outof and retract into said main chassis for storing and ejecting saidoptical disk; a turntable for rotatably supporting said optical diskstored; a rotatable drive source mechanism for rotatably driving saidturntable; a turntable raising/lowering mechanism for vertically movingsaid turntable between a lowered position in which interference withsaid optical disk stored or ejected is avoided and a raised position inwhich said optical disk stored is supportable; an optical pickup forrecording a signal on said optical disk supported by said turntable orreproducing a signal; a pickup drive mechanism for reciprocally movingsaid optical pickup between an inner region and an outer region of saidoptical disk supported by said turntable; a dual-purpose drive sourcemechanism for generating a driving force for said turntableraising/lowering mechanism and said pickup drive mechanism, where saiddual-purpose drive source mechanism includes a dual-purpose motor, and apower transmission mechanism including a gear element rotating under arotatable driving force of said dual-purpose motor; a first operationswitching mechanism for performing a first switching operation forswitching a transmission path of said driving force of said dual-purposedrive source mechanism from a path leading to said pickup drivemechanism to a path leading to said turntable raising/loweringmechanism, or vice versa, where said first operation switching mechanismperforms said first switching operation by an operation independent ofsaid optical pickup under said driving force of said dual-purpose drivesource mechanism; and a traverse chassis having a pivotal displacementside end portion on one end side thereof and a pivot axis side endportion on the other end side thereof, said pivot axis side end portionbeing pivotably mounted to said main chassis so that said pivotaldisplacement side end portion is movable toward and away from said mainchassis, said turntable being moved to said raised position by movingsaid pivotal displacement side end portion toward said main chassis,said turntable being moved to said lowered position by moving saidpivotal displacement side end portion away from said main chassis, andwhere said turntable, said rotatable drive source mechanism, saidoptical pickup, said dual-purpose drive source mechanism and said firstoperation switching mechanism are provided on said traverse chassis;wherein said pickup drive mechanism includes a rack portion providedintegrally with said optical pickup for moving said optical pickup undersaid rotatable driving force of said dual-purpose motor through saidgear element; wherein said first operation switching mechanism includesa slide rack movable under said rotatable driving force of saiddual-purpose motor through said gear element, with said rack portionhaving moved to a position in which said transmission path of saiddriving force from at least said gear element is interrupted, andperforms said first switching operation by moving said slide rack, withsaid optical pickup placed in a fixed position and where said firstoperation switching mechanism further includes a trigger plate moving inaccordance with the movement of said slide rack; and wherein saidturntable raising/lowering mechanism includes a driven boss provided onsaid pivotal displacement side end portion of said traverse chassis, anda slider member having a cam groove engageable with the driven boss andprovided on the main chassis movably in accordance with the movement ofsaid trigger plate, and where the movement of said slider member inaccordance with the movement of said trigger plate causes the drivenboss moving in said cam groove to move toward or away from said mainchassis, thereby moving said pivotal displacement side end portion ofsaid traverse chassis toward or away from said main chassis.
 2. Theoptical disk device according to claim 1, further comprising: a disktray transport mechanism for moving said disk tray to extend out of andretract into said main chassis under the driving force of saiddual-purpose drive source mechanism; and a second operation switchingmechanism for performing a second switching operation for switching thetransmission path of the driving force of said dual-purpose drive sourcemechanism from a path leading to said pickup drive mechanism to a pathleading to said disk tray transport mechanism, or vice versa, whereinsaid main chassis is provided with a tray gear having a first gearportion and a second gear portion and rotatable under the driving forceof said dual-purpose drive source mechanism, wherein said slider memberhas a slider-specific rack portion meshingly engageable with said firstgear portion, wherein said disk tray transport mechanism has a tray rackportion extending in a direction in which said disk tray is extended andretracted and meshingly engageable with said second gear portion,wherein said second operation switching mechanism has a tray guidegroove and a boss portion, said tray guide groove being provided in saiddisk tray and including in a continuous fashion a first guide grooveextending along a direction orthogonal to said direction in which saiddisk tray is extended and retracted, a second guide groove angled tosaid direction in which said disk tray is extended and retracted, and athird guide groove extending along said direction in which said disktray is extended and retracted, said boss portion being provided on saidslider portion and moving in said tray guide groove, and wherein saidfirst gear portion is in meshing engagement with said slider-specificrack portion and said tray gear rotates to move said slider memberduring an interval that said boss portion passes through said firstguide groove; said disk tray moves to extend or retract under a force ofmovement of said boss portion in said second guide groove, therebycausing a transition from the meshing engagement between said first gearportion and said slider-specific rack portion to meshing engagementbetween said second gear portion and said tray rack portion or viceversa during an interval that said boss portion passes through saidsecond guide groove; and said second gear portion is in meshingengagement with said tray rack portion and said tray gear rotates tomove said disk tray to extend and retract during an interval that saidboss portion passes through said third guide groove.
 3. The optical diskdevice according to claim 2, wherein said first gear portion has a pitchcircle radius smaller than that of said second gear portion.
 4. Theoptical disk device according to claim 3, wherein said first gearportion and said second gear portion are equal in the number of teeth toeach other.
 5. The optical disk device according to claim 1, whereinsaid trigger plate has a tooth portion, and wherein the driving forcefrom said dual-purpose drive source mechanism is transmitted throughsaid tooth portion in the course of the movement of said trigger plate.6. The optical disk device according to claim 5, wherein a speed atwhich said slider member moves said trigger plate is approximately equalto a speed at which said slider member is moved under the driving forcefrom said dual-purpose drive source mechanism through said toothportion.
 7. The optical disk device according to claim 1, furthercomprising an urging member for urging said slider member toward one endof a movable range thereof.
 8. The optical disk device according toclaim 1, wherein said dual-purpose drive source mechanism moves saidoptical pickup once stored toward the outer region of the optical diskafter power is turned on.
 9. The optical disk device according to claim1, wherein said trigger plate has a malfunction prevention wall forabutting against said optical pickup side or said slide rack side toinhibit its own movement prior to the operation of placing said opticalpickup in the inner region of the optical disk and the operation ofswitching the transmission path of the driving force of saiddual-purpose drive source mechanism from the path leading to said pickupdrive mechanism to the path leading to said turntable raising/loweringmechanism.
 10. The optical disk device according to claim 1, wherein afirst detector for detecting whether or not said disk tray is in anextended position based on a position to which said slider member ismoved, and a second detector for detecting a position to which saidoptical pickup is moved are provided on said traverse chassis side. 11.The optical disk device according to claim 10, wherein said traversechassis is provided with a relay substrate, and wherein said firstdetector and said second detector are provided on said relay substrate.